This invention relates to a cotton harvester and more specifically to the support arrangement and discharge structure for individual row units of the harvester.
Conventional cotton harvesters of the type shown, for example, in U.S. Pat. Nos. 3,373,547, 3,378,309, 3,464,191 and 3,515,437 utilizing individual row units with vertical picker drums and doffer assemblies have for the most part been limited to harvesting two rows at a time. Each row unit is relatively heavy, and adequately supporting more than two units while maintaining a narrow chassis and keeping the proper wheel spacing in relation to the rows of cotton has been a continuing source of difficulty. Each picking unit includes two picker drums with numerous picker bars mounting a plurality of gear-driven spindles for removing cotton from the plant. In addition, a doffer assembly with numerous doffer pads is provided for each picker drum to remove the cotton from the spindles. Although the weight of the components has been reduced by using lighter materials and smaller sizes, the individual units are still relatively heavy and put a considerable amount of mass in motion during operation thereby necessitating a sturdy support structure.
Typical of previous self-propelled two-row cotton pickers, the individual row units are supported forwardly of and between transversely spaced drive wheels by inner and outer lift arms connected to a transverse rock shaft near the forward end of the harvester frame. The row units include a housing having a sheet and panel construction of the type shown in U.S. Pat. No. 2,803,938. The housing has an upper box-like structure from which depend a pair of compartments each containing a picking drum and associated mechanism. Stabilizer bars extend from the harvester frame between the wheels to the lower rear of each compartment of the picking units for fore-and-aft support to prevent the unit from collapsing if it strikes an obstruction or is grounded, and also for adjusting the front to rear slope of the units. To add outboard units to increase capacity from two to four rows without widening the frame has heretofore been a problem since there has been no practical way to support and provide stabilization for the outboard units. Previous designs for a four-row harvester included transverse horizontal beams mounted at the rear of the main frame and carrying rock shaft and lower support braces for supporting the outboard picking units outwardly of and behind the forward wheels. Such a harvester is described in U.S. Pat. No. 3,176,451. Rear-mounted units are difficult for the operator to view, and the horizontal beams widen the rear of the main frame making the harvester harder to maneuver. The widened rear end adds too much weight to the rear steering wheels and also prevents a cotton receiver from being moved in closely to the basket during dumping.
In another four-row harvester, described in U.S. Pat. No. 3,031,828, a pair of unitary housing structures, each carrying two picking units, are mounted on opposite sides of the center line of the harvester. A pair of upper lift arms connected to a rock shaft and a lower stabilizer inside the drive wheels support each housing on the frame. The unitary housing structure is heavy and difficult to assemble and mount. The gears that drive the four picker drums often become misaligned as the large housing twists or bends slightly. Adjusting the units for varying row widths is not possible, and servicing the picker drums and doffers is difficult because of the unitary structure. The four-row harvesters typical of the prior art present problems during transportation because of their width. Narrowing the harvesters for transport is very time consuming and requires large equipment particularly when a unitary two-row housing structure is utilized.
It is known to provide a single compartment rearwardly of the housing structure that is adapted to receive cotton from a pair of upright harvesting drums that are positioned inwardly of a pair of adjacent rows of cotton plants. Such a housing is shown, for example, in U.S. Pat. No. 3,464,191. Doffing mechanisms associated with each of the drums removes the cotton from the spindles on the drums and discharge it rearwardly to the compartment through openings in the housing. An air duct then sucks the cotton from the compartment and conveys it upwardly to a basket on the harvester. Forwardly of the first harvesting drums are a second pair of harvesting drums located outwardly of the adjacent rows of parallel cotton plants, such as shown in U.S. Pat. No. 3,088,262. Commonly, a side compartment associated with each of the forward drums is provided for receiving cotton from the doffing mechanisms. The spindles on the forward drums are the first to contact the rows of cotton plants and therefore remove a higher volume of the cotton from the plants than do the spindles on the rear drums. The side compartments, which must be of adequate size to receive the high volume of cotton from the harvesting area, extend outwardly from the units thereby widening the front of the cotton harvester. The side compartments decrease maneuverability and prevent mounting of additional harvesting units to increase cotton harvester capacity to greater than two rows. Moving the compartments rearwardly of the harvesting unit results in the units extending too far forwardly on the harvester frame, and making the harvester front heavy.
In the aforementioned U.S. Pat. No. 3,031,828, there is shown a four-row cotton harvester in which a rear wall structure in the unitary housing structure receives cotton doffed from a pair of forward harvesting drums. Side compartments for receiving doffed cotton are eliminated, but assembly of the harvester and servicing of the doffers and drums are very difficult because of the structure. To service the doffers and the drums on such a harvester, the operator often has to crawl under or on top of the compartment.